Control apparatus for radio receivers



y r A. w. PLENSLER 2,243,487

CONTROL APPARATUS FOR RADIO RECEIVERS Filed Sept. 13, 1938 2 Sheeizs-Sheet l 0 O f/ .5; A

' E 4 j! jy' Z n u 3 9 Q j 9/ O dial 012%) %mr Patented May 27, 1941 Alexander W. Plensler, Chicago, Belmont Radio Corporation,

Illinois Ill., assignor to a corporation of Application September 13, 1938, Serial No. 229,728

16 Claims.

My invention relates in general to control apparatus, and more in particular to control apparatus of the so-called automatic type for tuning radio receivers. The present application is a continuation in part of my copending application, Serial No. 170,070, filed October 20, 1937, now Patent No. 2,130,153, issued September 13, 1938.

In both electrically operated and mechanically operated control apparatus, and particularly in such apparatus for radio receivers, a very satisfactory control structure has been employed wherein a plurality of control members such as discs, cams, and the like, are mounted upon a rotary shaft in predetermined angular control positions. The control members are normally retained on the shaft under frictional pressure against angular movementrelative to the shaft, but such pressure may be varied so as to permit angular adjustment of a control member relative to the shaft when the pressure is decreased.

Various means have been disclosed for varying such frictional pressure on the control members including the structure of the above noted copending application. This structure has proven very satisfactory commercially.- Additional means, however, will be disclosed-herein which comprises other satisfactory solutions of the general problem of setting and retaining control members at predetermined control positions. The structure of the present invention may be adopted to control apparatus utilizing the cam and lever elements of the device of the copending application as well as to many other types of control apparatus.

According to the present invention, structure is provided whereby the tuning means for a radio receiver may be manually operated and the frictional pressure on the control members associated with such means varied, not only from a position adjacent the side wall of a radio receiver cabinet in which the control apparatus is installed, but also from the front, and even from the rear of the radio receiver cabinet.

In control apparatus of the general type described above, and wherein manually movable rods, levers, or the like have been employed to mechanically move the control members on a rotary shaft, such rods, levers, or the like, normally were spring pressed and returned to their original idle position immediately after the opthe operator was listening, that the operator could subsequently tell what particular station he had tuned in. In the present invention I provide latching means associated with the frictional pressure varying and manually tuning structure to retain a manually movable rod, lever, or the like in an operative position so as to contrast it with the remainder of such elements in idle position. Such a position is retained until another such element is operated to change the tuning position of the apparatus.

One of the objects of the present invention is to provide simplified, relatively inexpensive, and sturdy control apparatus wherein the control members therefor may be frictionally retained in predetermined control positions, and the frictional pressure thereon varied without the use of extraneous tools from any position about the cabinet or the like for such apparatus.

Other objects, features, and advantages of my invention will be apparent from the following description taken with the drawings in which:

Fig. 1 is a top plan view of the complete control apparatus, with the tuning condenser for a radio receiver associated therewith shown in a fragmentary portion.

Fig. 2 is a cross-sectional view along the lines 2-2 of Fig. 1 and looking in the direction of the arrow on such line, showing the manually movable control lever in idle position, Fig. 3 is a view similar to that of Fig. 2 showing the structure of Fig. 2 with the lever in a latched indicating position after completing a tuning operation.

erators finger was removed, and the tuning operation completed. As a result it was only by being able to associate the dial or tuning scale indication with the particular station to which Fig. 6 is a fragmentary cross-sectional viewv looking toward the left in the illustration in Figs. 4 and 5 with the large tuning wheel removed, but showing the structure in position to permit manual rotation of the tuning shaft over the entire tuning range.

Fig. 7 is a fragmentary detailed view partly in section of a modified embodiment of the structure for varying the frictional pressure on the control members of the apparatus of Fig. 1.

Fig. 8 is a cross-sectional view of a further modification of frictional pressure varying structure for use with the control member structure of Fig. 1. I

Fig, 9 is a fragmentary view partly in section of a still further modification of frictional pressure varying structure for use with the control member structure of Fig. 1.

The control apparatus of the present invention includes a frame having a pair of end plates Ill and II which are mounted on a radio receiver chassis,'or other similar apparatus. Avariable condenser l2 for the radio. receiver is supported from the frame plate l and utilizes the rotary shaft |3 for the control apparatus, or is coupled thereto in any desired manner. A plurality of control members l4 are likewise carried on the shaft l3. The control members l4 as illustrated is secured to the shaft l3 against movement by means of a set screw 38 or the like. The tuning comprise heart-shaped cams. It is understood,

however, that many other configurations for both mechanical and electrical apparatus may be similarlymounted upon a rotary control shaft to be used with the structure of the present invention as will be apparent hereinafter. Each member I4 is rotatable with reference to the shaft l3, but is normally retained against rotation by means including friction washers l6 which are axially movable upon the shaft l3 but keyed against rotation by means of a projection |1 carried in a keyway l8 in the shaft. A friction washer I6 is supported on each side of each control member I4 in frictional engagement therewith. Intermediate the washers l6 are sleeves i9 which are both axially slidable and rotatable upon the shaft Hi. The entire assembly of control members, friction washers, and sleeves, can move axially on the shaft and be compressed to increase the frictional pressure on the members therein, or it will open up to decrease the frictional pressure on each control member II. A stop such as 2| secured to the shaft l3 at the left-hand end, as viewed in Fig. 1, acts to limit the movement to the left of such assembly by frictional pressure varying means at the righthand end.

At the right-hand end of the axially slidable assembly, a spring washer 22 is normally carried intermediate 9. pair of friction washers IS, with a sleeve l9 adjacent thereto and in engagement with the outside friction washer. An internally threaded bushing 23 is in engagement with the sleeve l9 and is threadably adjustable axially on the shaft i3 to compress the control member assembly when adjusted to the left, as viewed in Fig. l, or permit it to open up upon movement to the right with the consequent reduction in frictional pressure on the control members H in the assembly.

The threaded bushing 23 is adjusted by means of a crown gear 24 rigidly secured to a sliding sleeve 23' keyed to said bushing against rotation, but slidable axially relative thereto. This sliding connection causes the gear 24 to remain in engagement with a pinion gear 26. The gear 24 is, of course, rotated by the pinion gear 26 secured-to a shaft 21. The shaft is rotated by a knob 28 at the outer end thereof, and available at the outside of the front wall 29 (Fig. 1) of the radio receiver cabinet. Rotatably supported on the shaft 21 is a toothed gear 3| which is retained against axial movement by a collar 32 secured to the shaft 21 on one side of the gear and a shoulder cut in the shaft on the other side of the gear. A stamped-out tuning wheel 33 is secured rigidly on a bushing 34 which in turn wheel is employed to rotate the shaft l3 for ordinary normal tuning. A plurality of radially extending openings 31 (Fig 2) are cut in the substantially cup-shaped rim of the wheel 33 with a strap portion 38 remaining in the body of the rim intermediate each two perforations.

Frictional pressure is exerted on the control members l4 in order to hold them against angular movement on the shaft l3, and the pressure is decreased or removed in order to permit an angular adjustment of the control members to predetermined control positions as will be hereinafter described. When it is desired to vary the frictional pressure on the control members i4, the tuning knob 28 is pulled outwardly from the position shown in Fig. 5 to the position shown in Fig. 4. In the latter position one of the teeth of the gear 3| slides into an opening 31 in the wheel 33 so that a strap portion 38 on each side of the opening rests in the usual two cavities, one on each side of the tooth of the gear. At the opposite side of the gear 3|, and during the outward movement of the knob 28and the associated shaft 21, the gear is positioned so that a pair of teeth in the same straddle a lug 39 extending at right angles to a bracket 4| integral therewith (Fig. 6) which is secured to the outside of the frame plate Inasmuch as the bracket 4| is rigid and the gear 3| is rigidly retained thereon, the wheel 33 is maintained rigidly with reference to the gear 3| as a result of the holding connection between the wheel and gear.

As is clear from Fig. 4, when the gear 3| is pulled into locking position with the wheel 33 to thus maintain the shaft l3 rigid, the pinion gear 26 is also pulled into mesh with the teeth on the crown gear 24. The shaft 21 rotates in the gear 3| and upon rotating the knob 28 clockwise or counterclockwise, depending upon whether it is desired to increase or decrease the frictional pressure on -the control members i4, the pinion gear 26 is rotated to move the crown gear 24 therewith. The latter secured to the threaded bushing 23 threadably adjusts such bushing to the left as viewed in Figs. 1 and 4,

for instance, to increase the frictional pressure on the control members l4 or threadably adjusts the bushing 23 to the right to permit the assembly of control members, washers, and sleeves, to open up and thus decrease the frictional pressure on the control members i4. With the frictional pressure on the control members decreased the angular position of one or more of such control members may be changed with respect to-the shaft l3, to thus set a selected member in a position corresponding to a predetermined tuning position of the variable condenser l2 for the radio receiver.

In order to obtain the desired tuning position for the variable condenser l2, to subsequently position a control member, it is necessary to rotate the shaft l3 until the desired tuning is attained. This is accomplished by pressing the control knob 28 and the shaft 21 therewith from the locked position of Fig. 4 inwardly through the intermediate idle position illustrated in Fig. 5, and then to the manual tuning position as illustrated in Figs. 1 and 6'. With the knob 23 and shaft 21 in this position a rubber disc 44 secured to a beveled metal disc 48, which in turn is rigidly mounted on the shaft 21, engages a beveled flange 41 on the rim of the tuning wheel 33. In this 3| is out of locking position the toothed gear position with the wheel 33, and the pinion gear 25 is out of mesh with the crown gear 24. The wheel 33 secured to the shaft I3 is thus free to turn and be driven by the rubber disc 44 which frictionally engages the flange 41 as the operator rotates the knob 28. Locking means are provided to hold the disc 44 in this position of engagement so that it is not necessary for the operator to continue to push inwardly on the knob 28. This locking means will be more fully described hereinafter. The control apparatus has the usual indicating dial associated therewith, and the desired position of the variable condenser l2 can be ascertained from such dial.

When the variable condenser I2 is in a desired predetermined position, and consequently the shaft l3 in a corresponding desired angular posibe provided for each button corresponding to the tuned position of the control member l4 therewith. As mentioned above, when the button 5| on a lever 50 is in idle position, it appears the same as all of the remainingbuttons and levers, and it is therefore impossible to ascertain from an inspection of the buttons as to which-broadcast station is being received. In order to indicate the station to which the control apparatus has just tuned the condenser, latching means are provided ,which comprise a substantially U- shaped bar 51 pivotally supported on the end plates I and II at a point indicated by the reference character 58. A coiled spring .59 is secured at one end to a rod GI and at the other end to the latching bar 51 to pull the same downtion, the setting operation for the control apparatus may be carried out and the control members l4 may each be individually adjusted in turn on the shaft I 3 to correspond to a predetermined tuning position of the condenser I2. This is accomplished by depressing a lever 50 having a finger button at the end thereof available on the outside of the cabinet. The levers 50 correspond in number to the control members I4 and are rotatably supported upon a rigid shaft 52 carried in the frame end plates l0 and II. The selected lever 50 is depressed until the roller 53 on the inside end thereof engages the surface of a corresponding cam or control member l4, and then by continued movement of the lever the control member is rotated on the shaft l3 until the roller 53 is seated in the cavity 54 in the control member. In the meantime the operator holds the knob 25, and thus holds the shaft l3 against movement so that the predetermined tuned position of the condenser I2 is retained. After the angular adjustment of the control member l4, the lever 50 is returned to idle position and the same procedure may be followed with each of the control members I 4. Normally enough frictional pressure will remain on each of the control members l4 even with the bushing 23 in its non-friction position so that each control member l4 will retain its set position while the same procedure is followed for the other members.

After all, or any desired number of the control members l4 have been set to the desired tuning position, the knob 28 may again be pulled outwardly to the frictional pressure on the control members increased by rotating the knob in a friction increasing direction. When this operation is completed the knob 28 and shaft 21 are pressed inwardly to the idle position illustrated in Fig. 5. and the shaft l3, with the control members 14 rigid thereon, can be automatically rotated to predetermined tuning positions for the condenser l2 by depressing buttons 5| and the levers 50 therewith for engagement with the control members to rotate the same until a roller 53 seats in a cavity 54 as previously described.

Of course, the tuning condenser "can be adjusted to only a single broadcast station at a single time. Consequently only a single control unit comprising a. control member l4 and lever 50 is operated at one time. Each lever 50 is retained on the shaft 52 by means of a hairpin spring 55 (Figs. 2 and 3) and this spring also acts to normally return the lever 50 to the idle position shown in Fig. 2. In accordance with the usual practice a station identification tab may 75- position shown in Fig. 4 and the wardly against the top edge of the lever 50 as shown in Fig. 2. The bar 51, in idle position, rests at the bottom of a beveled edge on a projection 52 integral with the lever 50. The inside edge, or the edge toward the control member 14, for each projection 62 is straight and provided at such an angle that when in latched position as shown in Fig. 3 it is substantially parallel with the front face of the latch bar 51 against which it rests. When a lever 50 is depressed, the latch bar 51 rides on the beveled edge ofthe projection 52 until the lever is substantially in seated position with reference to the corresponding control member l4. This is the position corresponding to that illustrated in Fig. 3 and in this position the spring 59 pulls downwardly on the latching bar 51 to drop it behind the projection 82. The tension of the spring 55 on the lever tends to hold the straight face of the projection 52 in engagement with the front face of the latch bar 51. The depressed position of a lever 501s maintained until it is desired to tune the radio receiver to another station by pushing another button 5|. When this is done the latch bar is raised .by riding upwardly on the beveled face on the pivoted upwardly to idle position.

The number of stations to which a receiver can be turned automatically is limited to the number of control units including a lever and control member. If it is desired to tune the radio receiver to a station other than that for which the control units are set, this must be done by rotating the manual tuning knob 28. An extension 63 is provided on the latch bar 5'! on the outside of the frame plate II to cooperate with the friction varying and tuning structure including the control knob 28, and also to operate with a latching function. 53 includesan integral arm 84 (Fig. 6) lying above the shaft 21 and in alignment therewith. Thearm 54 includes a latching tooth 65 extending downwardly toward the shaft 21 and having a beveled edge on'the front thereof and a vertical edge on'the back thereof adjacent a recess 61 extending from the lower'edge of the arm. When the control knob 28 and the associated shaft 2'! is pressed inwardly from a friction varying position as shown in 'Fig. 4, or in idle position asshown in Fig. 5, to a manual tuning position as shown in Fig. 6, the beveled edge of the metal disc 46 engages the beveled front edge tension of spring 55 is The, extension disc 48 is engaged as described, the rubber disc 44 is in frictional engagement with the flange 41 on the tuning wheel 33. This position and the subsequent operation have been heretofore described.

As the knob 28 and associated shaft are being pushed into the position of Fig. 6, the arm 84 is raised to raise the latch bar 51 in the same manner as that accomplished when a lever 58 is depressed, as described above. Thus when the knob 28 is being rotated for manual tuning of the condenser, the levers 58 are all in idle position with the rollers 53 thereon spaced from the path of rotation of the control members 14 sufficiently so that there will be no engagement therewith to stop the rotation of the shaft 13.

similarly when the knob 28 is in manual tuning position as illustrated in Fig. 6, and it is desired to automatically tune the condenser to one of the predetermined positions represented by the levers 58, upon depressing a selector lever, the latch bar 51 is raised in the manner described, and the knob 28 and shaft 21 under pressure from the coil spring 89 carried on the shaft 21 intermediate the knob 28 and a bushing 1|, are pressed outwardly to the idle position of Fig. 5. In this position the rubber disc 44 is out of engagement with the wheel 33 and the shaft 13 may be rotated by movement of a lever 58 without at the same time rotating the shaft 21 and knob 28 structure which would put an additional load on the shaft 13.

The embodiment of my invention illustrated in Figs. 1 to 6 is normally employed. where it is necessary or desirable to accomplish manual tuning and frictional pressure variation from the front of the radio receiver cabinet rather than from the end thereof. Where it is desired to manually tune the condenser 12 throughout the effective range thereof, and change the frictional pressure on the control apparatus, this may be accomplished by the modification shown in Fig. '7. This structure comprises an internally threaded gear 14 threadedly secured on the threaded portion of the shaft l3 corresponding to the shaft l3 of Fig. 1, and carrying the control members 14 thereon in the identical manner previously described. The hub for the gear 14 extends through an aperture in the end plate H of the tuner frame and serves to support the shaft 13' therein. The threaded gear 14 is operatively connected with the axially slidable control member assembly. A rotatable knob 18 is frictionally retained on the outer end 11 of the shaft 13', with such end of such a configuration as to retain the knob against rotation. The stub shaft for the knob 18 extends through an aperture in the end wall 18 of the radio receiver cabinet. A pinion gear 18 for meshing with the gear 14 is secured to a stub shaft 81 journalled in the end plate II" which also extends through the end wall 18 of the receiver cabinet. A spring 82 on the stub shaft 81 intermediate 9. fixed washer and the end plate H, acts to normally press the shaft 8| outwardly so that the gears 19 is out of mesh with the gear 14.

In the illustration of Fig. 7 the structure is shown with the control assembly in reduced friction position. The spring washer 22 is in open position and the frictional'pressure is reduced intermediate the control members 14 and their corresponding washers so that the control members can be individually angularly adjusted as previously described. Assuming that the control members are set as desired, and the frictional pressure is to be increased on the members l4, the shaft I8 is turned in a clockwise or counterclockwise direction depending upon the direction of the threads on the gear 14 and the shaft l8 until the stop arm 83 (Fig. 1) keyed to the rotary shaft engages one of the two stop lugs 84 stamped out of the end plate 18 and positioned to correspond with the limits of rotation for the tuning condenser l2. The shaft 13' cannot rotate further beyond the engaged position of the stop arm 88 and a lug 84, and the knob 18 is then slipped off the shaft l8 and placed over a similarly shaped end on the stub shaft 81 for the pinion gear 18. Merely for purposes of illustration the pinion gear 18 is shown in Fig. 7 in mesh with the gear 14, but it is normally pressed outwardly by the spring 82. Normally the shaft 8| would be pushed inwardly to mesh position and then rotating the knob 18, the gear 18, and consequently the gear 14, would be rotated in a direction such as to move the gear 14 axially to the left on the shaft 13' as viewed in Fig. '7. This, of course, would move the entire control member assembly to the left as previously described until the desired frictional pressure was obtained in such assembly. The knob 18 may then be pulled from the shaft 81, and replaced on the shaft l3 and the stub shaft 8| under pressure from the spring 82 will spring outwardly to separate the gears 18 and 14.

To reduce the frictional pressure in the control assembly, the same procedure is followed except that the shaft I3 is originally rotated in the opposite direction to bring the stop arm 83 against the opposite lug 84 from that which was utilized for the friction increasing operation. The tuning condenser l2 in the embodiment of Fig. '7 is normally moved throughout its effective range by means of the knob 18 directly on the shaft 13, although, of course, this can be accomplished through the gear 19.

A still further modification of the invention is illustrated in Fig. 8, with friction varying structure designed to be adapted for use with the control member assembly illustrated in Fig. 1 as well as the condenser, tuner frame, and the like therewith. In the structure of Fig. 8 an internally threaded gear 86 is threadably secured on the shaft l3" in a manner similar to the corresponding gear 24 in Fig. 1. The hub 81 for the gear extends through the end plate H for operative connection with a control member assembly as shown in Fig. 1. When it is desired to change the axial position of the gear 88 in order to vary the frictional pressure on the control members H, as previously described, a lever 88 pivotally mounted on the end plate H and extending either through the back 89 of the cabinet for the receiver, or if desired through the front wall thereof, is depressed to the position shown in Fig. 8. In this position a tooth 9| on the inner end of the lever engages a tooth in the gear 88. The shaft 13" is then rotated by a right-angled drive system operated from the front of the radio receiver cabinet, or by a knob as 98 (shown in dotted lines) similar to that in Fig. 7 at the end wall of the cabinet, and the relative axial position between the gear 88 and shaft I3 is changed. When the operator removes his finger from the lever 88, the spring 92 pulls it downwardly out of connection with the gear 88 and the latter is free to turn with the shaft l3".

In the modification illustrated in Fig. 9 an internally threaded sleeve or bushing 88 is threadably secured on the end of the rotary tuning shaft l3'. The sleeve 93 is in operative connection with the axially movable control assembly including control members I4 and the associated structure as described with reference to the device of Fig. l. The sleeve 93 likewise acts to support the shaft l3"-' in the end wall ll of the tuner frame. vA knob 94, or similar finger engaging member, may be slipped over the sleeve 93 and rigidly secured thereto by a set screw 96 or the like. A pin 91 is then inserted through a corresponding aperture in the ends of the shaft l3 and secured therein against removal. As illustrated in Fig. 9, the structure is in partially decreased frictional pressure position. Before adjusting the sleeve 93 and its associated knob 94 to the position illustrated, the shaft I9' is rotated in one direction or the other, depending upon the thread upon the shaft" I3'" and the sleeve 93, until the stop arm 83 engages a corresponding stop lug 84 as described above. The rotation of the knob 94 is then continued in the same direction, but with the shaft l3'" maintained against rotation the sleeve 93 will be threadably adjustablymoved to the right to permit the control assembly to openup and the frictional pressure to be decreased. This rotation of the knob 94 is continued until the shoulder 99 at the end of the sleeve 93 is in frictional engagement with a pin 91, or the like, and normalLv it is desired that this engagement be tight. This causes thesleeve 93 and knob 94 to be locked with the shaft l3'" and such shaft may then be rotated in the opposite direction by the knob to adjust it to a predetermined angular position corresponding to a desired tuning position for the condenser I! on the shaft l3"'. The sleeve 93, of course, extends through a side wall 98 of the radio receiver cabinet housing the control apparatus.

When all of the control members l4 have been set to desired tuning positions, the knob 94 may be rotated to rotate the shaft and bring the stop arm 83 keyed thereto against the opposite stop lug 94 to that mentioned above. With the shaft thus held against rotation the rotation of the knob 94 in the same direction is continued to threadably adjust the sleeve 93 to the left as shown in Fig. 9, and thus frictionally lock such sleeve in operative connection with the control assembly. This assembly, in the meantime, has been compressed until the control members l4 are frictionally engaged against angular rotation with reference to the shaft I3'. After this operation is completed the entire control apparatus is in condition to be operated either automatically by levers as 50, or the tuning shaft l3'" may be rotatedthroughout its entire range by the knob 94.

The disclosures of this application are illustrative and the invention is not to be limited by them. In fact, if modifications or improvements are not at once obvious, they may be devised in the course of time to make additional use of the broad ideas taught and covered by this application. The claims are intended to point out novel features and not to limit the invention except as may be required by the prior art.

I claim:

1. Control apparatus for a radio receiver including in combination a rotary shaft, a frame for carrying said shaft, a plurality of control members supported on said shaft, means-axially movable with said control members on said shaft for normally frlctionally retaining the members against angular rotation on said rotary shaft,

means for varying the friction on the control members on the rotary shaft and operatively connected therewith including a toothed wheel threadably secured on said rotary shaft, a second toothed wheel rotatably supported on said frame spaced from said rotary shaft and adapted for meshing with said first toothed wheel when the friction is varied and normally out of mesh at other times, finger engaging means for operative connection selectively with either said rotary shaft or said second toothed wheel for directly rotating either one or the other, and means for retaining the rotary shaft stationary while said first toothed wheel is rotated by the rotation of the second toothed wheel in mesh therewith.

" 2. In a tuning device for a radio receiver, a rotatable shaft having a thread portion at one endthereof, means for limiting rotation of said shaft to a predetermined path less than 360, a plurality of tuning selector elements on said shaft normally frictionally retained against rotation thereon, means for varying the frictional pressure on said elements with said shaft stopped at one of the limit points in said predetermined path, said means including a toothed wheel threadably supported at the thread portion on said shaft,-and an independently supported rotatable member for engaging said toothed wheel to rotate the same on the shaft with the shaft in said stopped position to vary the axial position of said toothed wheel on said shaft, and a finger engaging member for operative connectioneither with said shaft or said rotatable member for rotating the same.

3. Control apparatus for a radio receiver including in combination a rotary shaft, a plurality of control members supported on said shaft and normally frictionally retained against angular rotation relative to said rotary shaft, friction varying means operatively connected with said control members including an internally threaded unit threadably carried on said rotary shaft and axially adjustable thereon, a pivotally supported 'means for rotating the shaft while the unit is held to change they relative axial position between the shaft and said unit.

4. Control apparatus for a radio receiver including in combination a rotary shaft, a plurality of control members supported on said shaft and normally frictionally retained against angular rotation relative to said rotary shaft, means for varying the frictional pressure on said control members, said varying means including an internally threaded gear threadably carried on said rotary shaft and axially adjustable thereon in operative connection with said control members, means rigidly secured to said shaft adjacent said gear on the side thereof opposite the control members, means for holding said rigid means and said shaft stationary while rotating said gear, said holding means including a rotatable and longitudinally movable shaft, a toothed member non-axiall movable on said longitu-- said toothed member to hold said toothed memment with said threaded gear to rotate the latter and axially move the threaded gear relative to the rotary shaft.

5. In control apparatus, a rotary shaft, a plurality of frictionally engaged control members on said shaft, and means in operative connection with said control members for varying the frictional pressure thereon, said means including a toothed member threadably carried on said rotary shaft, a second shaft at right angles to said rotary shaft supported for axial and rotary movement, means fixed on said second shaft for selective meshing engagement with said toothed member to axially move the latter relative to said rotary shaft upon rotation of said second shaft, and means on said second shaft for operative connection with said rotary shaft to retain the latter stationary but permit the second shaft to rotate in said means on said second shaft to axially move said toothed member.

6. Control apparatus for a radio receiver including in combination, a rotary shaft, a plurality of control members supported on said shaft and norm'ally frictionally retained thereon against angular adjustment relative thereto, unit means having means for rotating said shaft for tuning control over the tuning range of the apparatus, a plurality of selector means corresponding in number to said control memberswith each selector means selectively engageable with a corresponding control member to move the control member to a predetermined tuning position, pivotally supported latch means for retaining a moved selector means substantially in tuned position, and being common to all of said selector means, with each of said selector means having a latching portion thereon engageable with said latch means to move the same to latching position, said unit means being longitudinally movable and including a latching member operatively engageable with said latch means for retaining said unit means in operative position for rotating said shaft, and with said latching means being releasable from a latched selector means or the latched unit means upon subsequent movement of another selector means.

7. Control apparatus for a radio receiver including in combination a rotary shaft, 8, plurality of control members supported on said shaft and normally frictionally retained thereon against angular adjustment relative thereto,

combination manual tuning and friction varying means operatively connected with said control members and said rotary shaft, with said combination means including a toothed member threadably carried on said rotary shaft for axial adjustment thereon, a tuning wheel fixedly secured on said rotary shaft adjacent said toothed member for manual rotation of said rotary shaft, and a second shaft positioned for axial and rotatable movement at right angles to said rotary shaft having a gear thereon for operating engagement with said toothed member and a driving member thereon for operating engagement with said tuning wheel to manually rotate the latter to rotate the rotary shaft therewith, with said second shaft being axially movable to bring one of said structures as between said gear and said driving member into an operating position, movable selector members for selectively moving said control members to automatically move said 2,248,487 n stationary together with said rigid means rotary shaft, and latching means for holding a movable selector member in moved position and holding the driving member in engagement with the tuning wheel depending upon whether the rotary shaft is automatically rotated or manually rotated.

8. Control apparatus for a radio receiver, including rotary control means, means for rotating said control means to predetermined tuned positions, and means for rotating said control means independently of said first mentioned rotating means to all tuned positions over the range of signal frequencies received by a radio receiver with such apparatus, said first mentioned rotating means including a plurality of selector members for selected operative connection with said rotary control means, said second mentioned rotating means including a. tuning wheel fixedly secured on said rotary control means and a friction unit having a friction disc for selected frictional engagement with said tuning wheel to rotate the latter, and movable latching means operatively common to said selector members and said friction disc for selectively latching either a selector member or said friction disc substantially in operated position.

9. Tuning apparatus for a radio receiver including in combination of a rotary shaft structure, a plurality of control members supported on said shaft and normally frictionally retained against angular rotation-relative thereto, a friction varying unit structure adjustably secured on said shaft in operative connection with said control members, manually operated spring-tensioned means normally independent of said friction varying unit structure and said rotary shaft structure operatively connectible with one of said two structures with one of said two structures being maintained stationary, while the other structure is rotated to change the relative axial position of said friction varying unit structure and said rotary shaft; structure, and means for manually rotating said rotary shaft structure to change the control position of said control members thereon, with said spring-tensi'oned means being out of operative connection engagement with said friction varying unit structure during such manually rotating operation.

10. Tuning apparatus for a radio receiver including in combination a rotary shaft, a plurality of control members supported on said shaft and normally frictionally retained against angular rotation relative thereto, a friction varying unit adjustably secured on said shaft in operative connection with said control members, manually operated spring-tensioned means normally independent of said friction varying unit manually movable into operative connection with said friction varying unit and maintainable in said operative connection while the relative axial position of the shaft and friction unit is changed to change the friction exerted by said unit on said control members, and means for manually rotating said shaft to change the control position of said control members, with said spring-tensioned means being out of engagement with said friction unit during such manual rotational operation for the control members.

11. Tuning apparatus for a radio receiver including a rotary shaft, stop means for limiting the rotation of said shaft, a plurality of control members supported on said shaft and normally frictionally retained against rotation relative thereto, a friction member operatively connected with said control members and mounted on said shaft for relative axial movement therewith to vary the frictional pressure on said control members, hand-engaged rotating means normally independent of said friction member but operatively connectible with said friction member to adjust said friction member when the rotary shaft is stopped by said stop means, driven means secured to said shaft independently of said friction member and always out of engagement with said friction member operatively connecting said hand-engaged means and said shaft during a setting operation of a control member when said hand-engaged means is entirely out of operative connection with said friction member and is acting to rotate said shaft to change the relative position of a control member and said shaft for tuning setting and a driving member on said hand-engaged means engaging said driven means to accomplish the operative connection between said hand-engaged means and said shaft.

12. Tuning apparatus for a radio receiver 'including incombination a rotary shaft, frame means for supporting said shaft, a stop on said shaft and corresponding stop means on said frame for engagement with the stop for limiting the rotary movement of the shaft, a plurality of control members supported on said shaft and normally frictionally retained against angular rotation relative to said shaft, means for varying the friction on the control members, including an internally threaded axially adjustable member on said shaft operatively connected with said control members, finger-engaging means for operative connection with said threaded member to rotate said member while said shaft is held ber and said shaft for a predetermined tuning setting of said control member.

13. In a tuning device for a radio receiver, a rotatable shaft having a thread portion at one .end thereof, means for limiting rotation of said shaft to a predetermined path less than 360", a

plurality of tuning control members on said shaft normally frictionally retained against rotation thereon, means for varying the frictional pressure on said members with said shaft stopped at one of the limit points in said predetermined path, said means including a first gear member threadably supported at the thread portion on said shaft, a second gear member rotatably supported independently of said shaft for engaging said first gear member to rotate the same on the shaft with the shaft in said stopped position to vary the axial position of said first gear member on said shaft, and knob-like means for separable operative connection either with said shaft or said second gear member for rotating the same.

14. In control apparatus for a radio receiver having a. rotary shaft, and a plurality of control members supported on said shaft, the combination of hand-tuning means for rotating said shaft to tuning positions over the tuning range of the apparatus, a plurality of selector units correlatter to a predetermined tuned position, movable latching means operatively commonto all of said selector units and said hand-tuning means for releasably retaining a moved selector member substantially in tuned position and said handtuning means in operating position, with each of said selector unit s having a latching portion thereon adapted to engage said movable latching means to move the same to latching position, said hand-tuning means including a linearly movable shaft and a latch-moving portion with the latter engaging the latching means for retaining the hand-tuning means in operative position for rotating the linear shaftto in turn move the rotary shaft, and with said movable latching means normally being released from a latched selector unit or the latched hand-tuning means upon subsequent movement of another selector unit.

15. In control apparatus for a radio receiver having a rotary shaft, a plurality of control members supported on said shaft, and a tuning member operatively connected to said rotary shaft, the combination of hand-tuning means for rotating said shaft to all tuning positions over the tuning range'of the apparatus, a plurality of selector units corresponding to said control member, with each selector unit adapted for selective engagement with a corresponding control member to move the latter to a predetermined tuned position, movable latching means operatively common to all of said selector units and said hand-tuning means for releasably retaining a moved selector member substantially in tuned position and said hand-tuning means in operating position, with each of said selector units having a latching .portion thereon adapted to engage said movable latching means tomove the same to a latching position, said hand-tuning means including a linearly movable and rotat connected with the rotary shaft, and a beveled sponding to said control members, with each selector unit adapted for selective engagement with a corresponding control member to move the latch moving portion, with the latter engaging the latching means for retaining the hand-tuning means in operating position to rotate the linear member and the rotary shaft, and with said movable latching means normally being released from a latched selector unit or the latched handtuning means upon subsequent movement of another selector unit.

16. In control apparatus for a radio receiver having rotary control means, with means for rotating the control means to predetermined tuned positions, and means normally independent of the first-mentioned rotating means for rotating the control means substantially over the tuning range of the receiver, the combination of a plurality of selector means in said first-mentioned rotating means, selectively connectible with said rotary control means, a rotatable driven member and a rotatable driving member selectively engageable therewith in said second-mentioned rotating means, hand-operated means operatively connected with said rotatable driving member to selectively move said driving member into engagement with said driven member, and movable latching means operatively common to the selector means and the driving member for selectively retaining a selector means in operative position relative to said rotary control means and the driving member in operative position relative to said driven member.

' ALEXANDER W. PLENSLER. 

